Climate more pressing than Brexit, say 71% of Britons – poll

That's because Brexit and climate emergencies are both essentially gradualist[0] topics. They are topics which will be sat on and dragged out for as long as possible because it's something to talk about in parliament. Brexit is something for them to do and make them look busy, but we all know Brexit and the climate emergency has been dragged out for far too long.

[0] https://en.wikipedia.org/wiki/Gradualism

Not a very meaningful poll, if you ask me. It's currently hot in Northern Europe and people are tired of the Brexit discussion, and the two issues do not have much to do with each other. It's like asking whether apples or oranges are more important.